I just had the nasty rude awakening that dye stock really does only last about six weeks. As it turns out a nasty snot like sludge grows in it. I found this out using golden yellow so it was particularly disgusting. Luckily I've been mixing solutions of only one or two cups at a time, so I tend to use it pretty fast. However I've still got plenty mixed up and stored under the sink.

Has anyone had any experience with putting dye stock in the fridge? How much longer does it last? I've got no kids, so I don't have to worry about that. I do store my dye in diet coke bottles, which my boyfriend is addicted to, but I'm sure if I store it on the back lower shelf we will avoid calling poison control.

I haven't tried the fridge so I don't know if that will make it last longer, but I do know they generally keep better in glass than in plastic. I use jars about the size of a mayo jar . . . Also, if it starts to settle, often heating the glass jar in a few inches of hot water will get it to dissolve again . . . I do this in the kitchen sink, not on the stove, and be sure to remove the lid before heating.

As for disposal: I was told that in general it is safe to dispose of the small amounts used in household dye projects down the drain if you are on the city sewer system, I don't know if its the same for a septic. Just be sure to flush with lots of water and to clean the sink really well afterward.

When I paint and need to keep the paints I've mixed, I store them on a wet palette in the refrigerator, otherwise they get moldy. I would think it works the same way with dyes, since they're similar. And, I do rinse small amounts of paint down the sink.

I am no expert, so I just generally do what Mikele suggests. Here is what Mikele says about dye storage:

No, I don’t refrigerate them, but you can, and they should last a while.There are 2 ways to mix dyes.Dye + soda ash in a squirt bottle = unstable and needs to go in fridge.ORDyes only in bottle, soak the item in soda ash right before dying. I’d recommend this unless she wants to minimize wetness, soda ash is cheap cheap cheap, and safe to dump down the drain. Liquid only (dyes + urea I think) only stays stable for a while, I ‘ve left them for many months, like 8 and they weren’t quite as bright but were effective. I usually save the dyes if something is left over, but end up dumping them because I don’t do it often anymore. I pour all the yellows and greens and blues together and see what color I get and go nuts and dyes towels, sheets, faded clothes, etc….If she wants better instructions than that (though she may know what I am talking about) I can send them.

If you are still using the Lanaset dyes, contact the Prochem company to find out how long you can store them once the dyes are mixed up in water. Prochem sells Lanasets as 'Sabreset' dyes, but they are the exact same thing. Also, there should be some info on their website about storage for different kinds of dyes.

I'm not certain from reading your first post here if the dye stock had gone moldy/mildewy, or if you simply had solid dye that had settled out of the solution. If you still have it, try heating it up by putting the bottle (glass would be best) under running hot water, like the way people do to heat up honey that's gotten too thick. If the dye goes back into solution, it should be ok to use.

I agree with the above post, it's better to store in glass than in plastic.